Audience measurement systems typically include one or more device meters to monitor the media presented by one or more media presentation devices located at a monitored site. Many such audience measurement systems also include one or more people meters to obtain information characterizing the composition(s) of the audience(s) in the vicinity of the media presentation device(s) being monitored. Prior people meters generally fall into two categories, namely, active people meters or passive people meters. An active people meter obtains audience information by actively prompting an audience member to press an input key or otherwise enter information via the people meter. A passive people meter obtains audience information by passively monitoring the audience, usually by using facial recognition techniques to identify the individual audience members included in the audience.